HPAI is a serious and highly contagious viral disease primarily affecting domestic and wild birds, caused by influenza A viruses, particularly subtypes H5 and H7. The disease results in high mortality rates in poultry, leading to significant economic losses and threats to food security, livelihoods, and biodiversity.

In recent years, HPAI has also been detected in mammals, including cattle, foxes, sea lions, and even domestic pets raising concerns about the virus’s ability to spread across species and its potential risks to human health.

HPAI viruses mutate rapidly, facilitating adaptation to new hosts, including mammals and potentially humans. The virus can spread through migratory wild birds, infected poultry, and contaminated environments. The economic consequences include massive culling operations, trade restrictions, and disruptions to poultry industries, often with downstream impacts on food availability and consumer prices.  Additionally, the potential for zoonotic spillover raises pandemic concerns, as human infection with HPAI viruses can result in serious disease or death.

Currently, the HPAI H5N1 virus (clade 2.3.4.4b) has become endemic in many regions, affecting poultry farms, wild birds, and mammals. Outbreaks have been reported in Africa, the Americas, Asia and Europe. Since October of 2022, over 3400 outbreaks have been reported globally. The virus has even reached Antarctica, impacting wildlife populations. 

Control measures such as culling infected animals,  vaccination, movement restrictions, and biosecurity improvements are being implemented to mitigate its impact.

Yes. In early 2024, HPAI H5N1 was detected in dairy cattle. The virus was found in raw milk, with affected cows showing mild to moderate symptoms, such as decreased milk production and abnormal milk consistency. While more research is needed, strong surveillance and biosecurity measures are crucial to preventing further spread.  

Although human infections remain rare, there have been reports of dairy workers testing positive for H5N1 after exposure to infected dairy cattle. These cases have generally been mild, with symptoms including conjunctivitis and flu-like illness. However, more serious illness including death is also possible, particularly when the person has other pre-existing conditions. The risk to the general public remains low, but farmers, veterinarians, and people in direct contact with infected animals or raw milk may have an increased risk of exposure and should use appropriate personal protective equipment.   

Regarding milk safety, the pasteurization process effectively inactivates the HPAI virus, making it safe to drink. However, consuming raw (unpasteurized) milk from infected cows could pose a potential risk. FAO strongly discourages the consumption of unpasteurized milk or dairy products from affected areas. 

FAO has outlined key strategies for HPAI control, including:

• Early detection: countries are encouraged to implement active and passive surveillance systems to identify outbreaks quickly.
• Laboratory testing: strengthening diagnostic protocols is essential for accurate detection and timely response.
• Biosecurity measures: farms must follow strict hygiene protocols, limit contact between wild and domestic animals, and control movement within value chains.
• Preparedness: effective risk-based prevention, contingency plan and risk management in place.
• Rapid response: infected animals should be effectively managed to reduce the risk of onward transmission, which may include culling, movement restrictions, safe carcass disposal or composting, and cleaning and disinfection of contaminated areas.
• Vaccination: vaccination programmes using well-matched vaccines can help to mitigate the impacts of HPAI when used as part of an overall HPAI control strategy.

Under a One Health approach, FAO collaborates with the World Organisation for Animal Health (WOAH), the World Health Organization (WHO), and other partners to:

• Promote international cooperation and facilitate real-time data sharing for monitoring, early warning, and risk assessment.
• Enhance preparedness, including strengthening laboratory diagnostic capacities and facilitate information sharing on epidemiological and virological findings.
• Develop and disseminate technical guidance on surveillance, prevention, and response strategies.
• Support national governments in establishing tailored HPAI control strategies and improved public awareness. 

FAO and WOAH, under the Global Framework for the Progressive Control of Transboundary Animal Diseases (GF-TADs), have developed a ten-year global strategy (2024-2033) to replace the 2008 version, to respond to the global challenges  posed by HPAI by adopting a One Health approach for sustainable poultry sector transformation. It aims to:

• Prevent HPAI outbreaks and their impact on human health and ecosystems through early detection and control across sectors. 
• Protect poultry value chains, livelihoods, trade, and the health of humans, animals, and ecosystems from HPAI impacts.
• Transform poultry value chains to improve resilience to HPAI and other disease threats, contributing to sustainable livestock production and mitigate pandemic risk.

Websites:

• FAO highly pathogenic avian influenza
• FAO situation updates:
• Global Avian Influenza Viruses with Zoonotic Potential
• Sub-Saharan Africa HPAI
• Emergency Prevention System for Animal Health (EMPRES-AH)
• Global Framework for the Progressive Control of Transboundary Animal Diseases (GF-TADs)

Publications:

• Global strategy for the prevention and control of high pathogenicity avian influenza (2024–2033)
• Recommendations for the surveillance of influenza A(H5N1) in cattle – with broader application to other farmed mammals
• A(H5N1) influenza in dairy cattle in the United States of America
• More